Curb box cap



Dec. 24, 1963 R. L. WHITMAN 3,115,267I

CURB` Boxy CAP Filed Aug. 23, 1961 INVENTOR ROBERT L. WH T MAN ATTORNEYUnited States Patent O 3,115,267 CURB BOX CAP Robert L. Whitman,laclrson, Mich., assigner to Handley Industries, Inc., Jackson, Mich., acorporation of Michigan Filed Aug. 23, 1961, Ser. No. 133,417 11 Claims.(Cl. 22h-24.5)

The invent-ion pertains to the curb box art and particularly rela-tes toa cover structure `for curb boxes.

yCurb boxes have long been employed to provide access to water and g-asvalves, or the like, buried in the ground. Such boxes primarily consistof a tube having the lower end thereof in communication with the valveand the upper end is normally coincident with, or slightly below, theground level. The upper end of -the box is provided with Ka cover whichis removed when access to the valve is desired.

It is an `object of the invention to provide curb box structure land acover therefor which permits the cover to be positively locked to thebox without the necessity of high torque or pressure forces.

A fur-ther object of the invention is to provide a curb box cover havinga radially extending projection or lip for positive locking engagementwith a recess formed in the curb box Vand means for radially translatingthe lip into the recess.

Yet another object of the invention is to provide a nonmagnetic curb boxcover which is highly resistant to corrosion and wherein magnet meansmay be employed to aid in the location of the curb box.

Yet another object of the invention is to provide a curb box structureemploying cam surface or wedge means for raffixing the cover to the boxwhe-rein the cam surfaces are uniquely arranged and permit `a morereadily manufacturable and dependable construction than heretofore knowncam actuated covers.

These Iand other objec-ts of the invention arising from the details andrelationships of the components of an embodiment thereof will becomeapparent from the 'following description and accompanying drawingwherein:

FIG. 1 is an elevational sectional view of the upper end of a curb boxand cover, in accord with the invention taken `along a section similarto section yli-II of FIG. 3, after placing the cover in position `andprior to actuation of the locking means,

FIG. 2 is an elevational sectional view similar to FlG. 1 taken alongsection II-ll of F-IG. 3 after actuation of the locking meansillustrating the cover in the locked position,

FIG. 3 is a plane sectional view taken along section III-lll of FIG. 2,and

FIG. 4 is a perspective enlarged upper view of the nut member employedin conjunction with the invention,

As shown in FIGS. 1 land 2, the upper region of the curb box consists ofa cylindrical member having a plurality of cylindrical portions ofvarying diameter. The particular conguration of the curb box is notcritical to the practice of the invention, except for the fact that thecurb box be provided with an internal shoulder 12 which may be definedby an iannular groove 14 formed on the inside of the box. In theillustrated embodiment both the curb box land the major cover componentsare formed of a synthetic, plastic material which is relatively inertand highly resistant to corrosion such as cellulose acetate, butyrate,iacrylonitrile, or the like. This material is also preferablynonmagnetic for reasons which later will be apparent.

The primary cover components include a cap element 16, a nut member 18,and a bolt or screw element rotatably 'associated with the cap andengaging a threaded 3,115,267 Patented Dec. Z4, lgl

hole in the nut. The cap member is of a configuration similar to that ofthe upper end of the curb box and includes a downward extending iiange22 to minimize the opportunity of foreign matter finding its wayadjacent the upper end of the box. The cap is provided with a centrallyrecessed portion 24 and is formed with a hole 26 through which the bolt2th extends. The bolt 2d includes a head 2'8 which will be locatedwithin the depression 24 and washer means are interposed between thehead and cap. It will be noted that the diameter of the hole 26 is`substantially greater than that of the threaded bolt portion.

The cap 16 lalso includes a downwardly extending projection portion 30,which extends in an axial direction into the curb box and exteriorlyconforms to `the inner configuration thereof. The projection 3i) outersurface is cylindrical and the projection extends in its upper regionsthrough an arc of approximately 200 and -at the lower end through an arcof approximately The lateral edges of the projection 30 will thereforebe o-f an inclined configuration and deiine cam or wedge surfaces 32.The surfaces 32 are preferably planar.

The configuration of the nut member 13 is best shown in FIG. 4 andincludes a hub portion 34 having a threaded bore 36 therein forreceiving the threaded bolt 20'. The lower end of the threaded bolt 2i?is deformed at 38 to prevent the nut from being completely unscrewedfrom the bolt. The nut 18 is formed of a congnration requiring laminimum amount of material, yet having sufficient strengthcharacteristics, and includes the reinforcing web portions 4i) whichradially extend from the hub. The exterior portion 42 of the nut is of acylindrical configuration dened at the edges thereof by planar camsurfaces 44. The cam surfaces 44 are such that the upper cylindricalportion extends through an -arc of substantially 160 and the lowerportion of the nut extends through approximately 200. The configurationof the cylindrical portion 42 substantially conforms to that of theinner curb box surface. The lower end of the cylindrical portion 42 isprovided with a lip or ridge 46 which radially extends from thecylindrical configuration thereof, having a maximum extension at thepoint furtherest from the plane of cam surfaces 44. The lip 46 is of anaxial length less than 4that of the groove 14, as will be apparent fromFIG. 2.

In operation, the cap and nut members 16 and 18 are assembled by meansof the bolt 24) wherein the nut 1S is loosely related to the cover andthe cam surfaces 44 are in loosely associated opposed and adjacentrelation to the wedge surfaces 32. The cover is then inserted upon theend of the curb box 1d and as the nut will be located on the lowerregions of the bolt member 20, the bolt may be moved to the extreme leftposition in the hole 26 as shown in FIG. l. This relationship reducesthe dimension from the maximum extension of the lip 46 to thediametrically opposed portion of the outer surface of the projection 30to less than the diameter of the curb box 16, and permits the nut andprojection to be easily inserted into the curb box to assume therelation shown in FIG. l. Thereupon, the bolt 20 is rotated to draw thenut 18 upwardly wherein the surfaces 44 will engage with the surfaces32, and move the nut to the right as the nut is moved upwardly towardthe bolt head 28. The resultant radial movement of the nut to the rightinserts the lip 46 into the groove 14 and continued rotation of the boltwill wedge the portions 30 and 42 against the curb box walls.

Merely tightening the bolt 18 with the fingers permits a coverconnection which prevents the cover being lifted from the curb box dueto the engagement of lip 46 with shoulder 12, and by the use of a wrenchto tighten the 3 bolt 29, a very firm connection between the curb boxand cover may be achieved.

Difficulty is often encountered in locating curb box covers in that theyoften become obscured from view by weeds, dirt, high grass, etc., and toaid in the use of magnetic curb box locating equipment, a magnet may beassociated with the cover in accord with the invention. A small magnetmay be' located in the nut between the reinforcing ribs 4b andmaintained therein by upsetting the rib portions above the magnet as atSti. Such upsetting may be accomplished with a heated tool, if the nutis formed of a thermoplastic material or formed cold, if desired. To aidin locating the curb box and cover when using electronic reflecting typemetal locating apparatus, a disc 51 of aluminum or foil may be placedupon the nut 1S to reiiect the signals of the apparatus. Also, magnets,not shown, are often mounted on the exterior of the curb box itl nearthe upper end for locating purposes if the cover should be lost.

in some instances it may be desirable to form the cap and nut componentsof cast iron or other metal, or the cover may be formed of cast iron andthe nut may be of synthetic material.' Usually the bolt is formed ofbrass to minimize corroding and permit easy actuation of the cover.

llt will be appreciated that various modifications to the invention maybe apparent to those skilled in the art, and it is intended that thescope of the invention be defined only by the following claims.

I claim:

l. A cover for curb boxes and the like including a tubular member havingan open end and an internal wall and a radial shoulder dened on the wallcomprising, in combination, a cap adapted to enclose the open end of thetubular member, a projection formed on said cap extending into thetubular member, a cam surface defined on said projection obliquelyrelated to the axis of said tubular member, a nut member, nut supportmeans interconnecting said cap and nut member selectively displacingsaid nut member toward and away from said cam surface and permittingradial displacement of said nut member relative to the axis of thetubular member upon engagement with said cam surface, means defined onsaid nut member engageable with said cam surface", and a radialextending shoulder defined on said nut member operatively associatingwith the tubular member shoulder in abutting relation upon operation ofsaid nut support means to engage said nut with said cam surface andtranslate said nut member relative to said cam surface.

2. A cover for curb boxes and the like including a tubular member havingan open end and an internal wall and a radial shoulder defined on thewall axially spaced from the end comprising, in combination, a capadapted to enclose the open end of the tubular member, a projectiondefined on said cap adapted to axially extend into the tubular member,an axial extending cam surface delined on said projection obliquelyrelated to the axis of said tubular member, a nut member having aprojection cam surface engaging portion defined thereon, meansinterconnecting said cap and nut members selectively axially displacingsaid nut member relative to said cap and permitting radial displacementof said nut member relative to said cap and a radial shoulder defined onsaid nut member adapted to radially overlap with said tubular membershoulder for abutting engagement therewith upon actuation of saidinterconnecting means engaging said nut member with said cam surface toprevent axial withdrawal of the cover from the tubular member.

3. In a cover as in claim 2 wherein a recess is defined in the wall ofthe tubular member forming the tubular member shoulder and a radialextending projection is defined on said nut member defining said nutmember shoulder and receivable within said recess.

4. In a cover as in claim 3 wherein said interconnecting means comprisesa threaded bolt rotatably associated with said cap and a threaded boredefined in said nut member receiving said bolt.

5. In a cover as in claim 4 wherein said cap projection is of an axialconfiguration corresponding to the configuration of the internal tubularmember wall and engages said wall, said cap projection having axialextending defining edges, said edges constituting cam surfaces.

6. In a cover as in claim 2 wherein said cap and nut member are formedof a synthetic, inert, nonmagnetic material, and a magnet is affixed tosaid nut member.

7. A curb box cover comprising, in combination, a cap having an axis, anaxial extending projection fixedly defined on said cap defined by alower edge and axial extending edges, said axial extending edgesconstituting cam surfaces, an axial hole centrally defined in said cap,a bolt having a head and loosely received within and. extending throughsaid hole, said head abuttingly associating with said cap, a nut memberoperatively associated with said bolt substantially axially aligned withsaid projection, said nut member including an axial extending portionhaving an abutment surface transversely disposed to the axial directionof said projection and cam surface engaging members defined on said nutmember on the opposite side thereof relative to said abutment surfaceadapted to engage said cam surfaces upon drawing said nut member towardsaid cap by rotating said bolt.

8. In a curb box cover as in claim 7 wherein said nut member is of asubstantially semi-cylindrical configuration and the axial edges thereofare complementary in configuration to said cam surfaces and constitutesaid cam engaging members.

9. In a curb box as in claim 7 wherein said cap and nut member areformed of a relatively inert synthetic, moldable material.

10. In a curb box cover as in claim 7 wherein said nut member is formedof a synthetic, inert, nonmagnetic material and a magnet affixed to saidnut member.

11. A curb box cover comprising, in combination, a cap portion having anaxis, an axial extending projection iixedly defined on said cap portionhaving a cylindrical outer surface and axially defined by cam surfaceedges obliquely related to the axis of said cap, said projectiondefining a cylindrical arcuate segment of about an axial hole centrallydefined in said cap portion, a bolt extending through said hole, saidbolt including a threaded shank which extends through said holefand anenlarged head abutting said cap portion, said `opening being larger thansaid threaded shank whereby said bolt is capable of lateral movementrelative to said cap p0rtion axis, a nut member threadedly mounted uponsaid bolt shank, said nut member constituting a cylindrical surfacedarcuate segment of about 180 axially defined by cam surface edgescomplementary to said first-mentioned cam surface edges whereby uponsaid nut member being axially aligned with said projection so that thecam surface edges of said projection and nut member engage, saidprojection and nut member together define a complete cylindricalconfiguration having an outer cylindrical surface, and a transverselydisposed abutment surface defined on said nut member on the outersurface thereof intermediate the cam surface edges of said nut member.

Russell Nov. 9, 1943 Handley Apr. 5, 1960

1. A COVER FOR CURB BOXES AND THE LIKE INCLUDING A TUBULAR MEMBER HAVINGAN OPEN END AND AN INTERNAL WALL AND A RADIAL SHOULDER DEFINED ON THEWALL COMPRISING, IN COMBINATION, A CAP ADAPTED TO ENCLOSE THE OPEN ENDOF THE TUBULAR MEMBER, A PROJECTION FORMED ON SAID CAP EXTENDING INTOTHE TUBULAR MEMBER, A CAM SURFACE DEFINED ON SAID PROJECTION OBLIQUELYRELATED TO THE AXIS OF SAID TUBULAR MEMBER, A NUT MEMBER, NUT SUPPORTMEANS INTERCONNECTING SAID CAP AND NUT MEMBER SELECTIVELY DISPLACINGSAID NUT MEMBER TOWARD AND AWAY FROM SAID CAM